Mathematics

The closeness of the 2000 U.S. presidential election highlighted the unusual characteristics of the American electoral system, such as the electoral college, in which all but a few states assign electoral votes on a winner-take-all basis, and simple plurality elections, in which the leading candidate wins without having a runoff election to establish a majority winner. Mathematicians and others had investigated voting systems in the past, and this contentious election inspired further research and discoveries in 2001. (See alsoWorld Affairs:United States: Sidebar.)

When there are only two candidates, the situation is very simple. In 1952 the American mathematician Kenneth May proved that there is only one voting system that treats all voters equally, that treats both candidates equally, and where the winning candidate would still win if he or she received more votes. That system is majority rule.

When there are more than two candidates, as was the case in the 2000 presidential election, the situation is most unsatisfactory. Two notable voting systems have been proposed as better for multicandidate races. The first is commonly attributed to the 18th-century French mathematician Jean-Charles, chevalier de Borda. Borda’s method requires each voter to rank the candidates, with the lowest candidate getting 1 point, the next lowest candidate 2 points, and so forth, up to the highest candidate, who gets as many points as there are candidates. The points from all voters are added, and the candidate with the most points wins. This system was actually first described in 1433 by Nicholas of Cusa, a German cardinal who was concerned with how to elect German kings. Today it is used in the United States to rank collegiate football and basketball teams.

Borda believed that his system was better than the one devised by his French contemporary Marie-Jean-Antoine-Nicolas de Caritat, marquis de Condorcet. Condorcet felt that the winner should be able to defeat every other candidate in a one-on-one contest. Unfortunately, not every election has a Condorcet winner. In the 2000 presidential election, however, polls indicated that Al Gore would have been a Condorcet winner, since—with the help of supporters of Ralph Nader—he would have beaten George W. Bush in a one-on-one contest (or in a runoff election).

Like the Borda system, the Condorcet system had already been proposed for ecclesiastical elections; it was first described in the 13th century by the Catalan philosopher and missionary Ramon Llull, who was interested in how to elect the abbess of a convent. Nicholas of Cusa made a copy of one of Llull’s manuscripts before deciding he could do better, by devising the Borda system. Another of Llull’s manuscripts, with a more complete description of his voting system, was discovered and published in 2001, by Friedrich Pukelsheim and others at the University of Augsberg, Germany.

Part of the reason for the great controversy between Borda and Condorcet was that neither of their systems was ideal. In fact, the American Nobel Prize-winning economist Kenneth Arrow showed in 1951 that no voting system for multicandidate elections can be both decisive (produce a Condorcet winner) and completely fair (candidates change position only with a change in their rankings). Nevertheless, after the 2000 presidential election, Americans Donald Saari and Steven Brams argued persuasively for modifying the U.S. system.

Saari used geometry in order to reveal hidden assumptions in voting methods. He favoured the Borda system, which he believed more accurately reflects the true sentiment of voters, as well as having a tendency to produce more centrist winners than the plurality method. In practice, ranking all the candidates can be onerous, and the “broadly supported” winner may just be everybody’s third or fourth choice.

Another criticism of the Borda system is that the electorate may vote strategically, rather than sincerely, in order to manipulate the election. Such strategic voting takes place under the current system; in the 2000 presidential election, many voters who preferred Nader voted for Gore instead of out of fear of giving the election to Bush.

Brams favoured approval voting, which is used by some professional societies; Venetians first used it in the 13th century to help elect their magistrates. Under approval voting, voters cast one vote for every candidate they regard as acceptable; the winner is the candidate with the most votes. Approval voting has several attractive features, such as the winner always having the broadest approval and voters never having to choose between two favoured candidates.

Saari and Brams both agreed that the plurality method, together with the winner-take-all feature of the electoral college, has fundamentally flawed the American electoral process, preventing the election of candidates with broad support and frustrating the will of the electorate.

Chemistry

Carbon Chemistry

In 2001 Hendrik Schön and associates of Lucent Technologies’ Bell Laboratories, Murray Hill, N.J., announced the production of buckminsterfullerene crystals that become superconducting at substantially warmer temperatures than previously possible. Superconductors conduct electric current without losses due to resistance when they are cooled below a certain critical temperature. In 1991 a Bell Labs team first showed that buckminsterfullerene molecules (C60), which are spherical hollow-cage structures made of 60 carbon atoms each, can act as superconductors at very low temperatures when doped with potassium atoms.

Schön’s group mixed C60 with chloroform (CHCl3) or its bromine analogue, bromoform, to create “stretched” C60 crystals. In the modified crystal structure, chloroform or bromoform molecules were wedged between C60 spheres, moving them farther apart. The altered spacing between neighbouring C60 molecules, coupled with the experimenters’ use of a setup that took advantage of transistor-like effects, raised the critical temperature of the material. Tests showed that C60 mixed with bromoform became superconducting below 117 K (−249 °F), which is more than double the previous temperature record of 52 K (−366 °F) for a C60-based material set the previous year.

Although still very cold, the record-breaking temperature was warm enough for the C60 superconductor to function while cooled by liquid nitrogen (boiling point 77 K [−321 °F]), instead of the lower-boiling and much more expensive liquid helium. The only other superconductors that operate at higher temperatures are copper oxide ceramic superconductors. These materials were used in powerful magnets, superconductive wires for power-transmission systems, and other applications, but they were expensive and had other drawbacks. Schön speculated that C60 superconductors could turn out to be cheaper. He also believed that increasing the spacing between C60 spheres in the crystal by just a small percentage could boost the critical temperature even more.

Mathematics and Physical Sciences: Year In Review 2001. (2015). In Encyclopædia Britannica. Retrieved from http://www.britannica.com/EBchecked/topic/1566015/Mathematics-and-Physical-Sciences-Year-In-Review-2001

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